Controllable fabrication of high purity Mg(OH)_2 nanoneedles via direct transformation of natural brucite

摘要

High purity Mg(OH)_2 nanoneedles with diameters of 3-5 nm and lengths of 40-60 nm were synthesized directly from natural brucite via a facile and dissolution-free route in the presence of magnesium sulfosalicylate and polyethylene glycol (PEG, MW1000). Under hydrothermal conditions, magnesium sulfosalicylate caused layered brucite to disintegrate into thin nanosheets and could transport hydroxyl groups from the nanosheets to Mg(OH)_2 crystal nuclei as a "supplier". The PEG1000 might regulate the one-dimensional morphology and improve the purity of the Mg(OH)_2 nanoneedles by forming selective hydrogen bonds on the related Mg(OH)_2 crystal surfaces. Since this novel approach is simple and low-cost in comparison with wet precipitation method, the process can easily be scaled up.